If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Nuclear winter a myth?

I've read and heard a lot about nuclear winters as a result of a nuclear war. For those of you not familair with the concept, many people have predicted that the detonation of many nuclear weapons in a nuclear war could throw enough sut and debris into the air to dim the sun significantly, which would have severe negative effects on the Earth's biosphere.

A recent study from 2006 asserted "With the exchange of 100 15-kiloton weapons as posed in this scenario, the estimated quantities of smoke generated could lead to global climate anomalies exceeding any changes experienced in recorded history," Robock said. "And that's just 0.03 percent of the total explosive power of the current world nuclear arsenal." That's a total yield of 1,500 kt

Yet it seems there is plenty of direct experimental evidence to the contrary. Since 1945 over 2,000 nuclear weapons have been detonated. In 1958 alone there were 140 atmospheric nuclear weapons tests, with a total yield of around 750,000 kt, many single bombs larger than all of those 50 bombs put together. The Tsar bomba, the largest bomb ever detonated, was over 35 times bigger than all of the bombs mentioned in that test combined.

So is the idea of nuclear winter a greatly exaggerated? Perhaps if the USA and Russia both loaded their entire arsenals onto each other.

My only other conclusion is that global warming is a result of the partial test ban treaty.

Colfax WA, neat I have a barn and 49 acres - I have 2 horses, 15 chickens - but no more pigs

Posts

10,968

Re: Nuclear winter a myth?

I think one factor you are missing is how tests vs glassing cities. The tests even the big ones were contained, planed etc (and often at sea). Real usage say for busting ICBM sites might throw up a lot more material and use on urban areas would almost assuredly spark large secondary firestorms that would presumably burn more or less uncontrollably (drop a couple bombs on Houston and you are going to have a lot petroleum fires burning for a long time). The same might go use in rural military targets as again forest fire, grass fire etc might essentially burn uncontaminated.

That's is all just off the cuff but it seems reasonable that tests were not a direct model of mass military use.

IN PATROCINIVM SVB Dromikaites

'One day when I fly with my hands - up down the sky, like a bird'

But if the cause be not good, the king himself hath a heavy reckoning to make, when all those legs and arms and heads, chopped off in battle, shall join together at the latter day and cry all 'We died at such a place; some swearing, some crying for surgeon, some upon their wives left poor behind them, some upon the debts they owe, some upon their children rawly left.

Hyperides of Athens: We know, replied he, that Antipater is good, but we (the Demos of Athens) have no need of a master at present, even a good one.

Re: Nuclear winter a myth?

But despite that, the testing used orders of magnitute more nuclear power than in their model. Even if they would not release the same proportion of sut in relation to their size, they were much bigger and there were far more of them?

Re: Nuclear winter a myth?

A lot would also have to do with how they weapons were used. Ground impacted nuclear weapons would throw up a lot more irradiated material (soil, debris, etc.) into the atmosphere, while weapons that are air burst will do a bit more physical damage to the target but cause less fallout. The idea would have been to air burst over targets like cities but underground installations like missile silos, command centers and the like would have been ground impacted.

Re: Nuclear winter a myth?

Originally Posted by irelandeb

I've read and heard a lot about nuclear winters as a result of a nuclear war. For those of you not familair with the concept, many people have predicted that the detonation of many nuclear weapons in a nuclear war could throw enough sut and debris into the air to dim the sun significantly, which would have severe negative effects on the Earth's biosphere.

A recent study from 2006 asserted "With the exchange of 100 15-kiloton weapons as posed in this scenario, the estimated quantities of smoke generated could lead to global climate anomalies exceeding any changes experienced in recorded history," Robock said. "And that's just 0.03 percent of the total explosive power of the current world nuclear arsenal." That's a total yield of 1,500 kt

Yet it seems there is plenty of direct experimental evidence to the contrary. Since 1945 over 2,000 nuclear weapons have been detonated. In 1958 alone there were 140 atmospheric nuclear weapons tests, with a total yield of around 750,000 kt, many single bombs larger than all of those 50 bombs put together. The Tsar bomba, the largest bomb ever detonated, was over 35 times bigger than all of the bombs mentioned in that test combined.

So is the idea of nuclear winter a greatly exaggerated? Perhaps if the USA and Russia both loaded their entire arsenals onto each other.

My only other conclusion is that global warming is a result of the partial test ban treaty.

Your title:

Nuclear winter a myth?

No, it isn't, not at all. The issue was already known decades ago, now today, such a scenario can be pretty accurately simulated.

Did you read the article overall, or stopped after the first paragraph?

I put it into spoilers here, so the average reader here has it a bit more comfortable:

Spoiler Alert, click show to read:

Regional Nuclear War Could Devastate Global Climate

ScienceDaily (Dec. 11, 2006) — Even a small-scale, regional nuclear war could produce as many direct fatalities as all of World War II and disrupt the global climate for a decade or more, with environmental effects that could be devastating for everyone on Earth, university researchers have found.

These powerful conclusions are being presented Dec. 11 during a press conference and a special technical session at the annual meeting of American Geophysical Union in San Francisco. The research also appears in twin papers posted on Atmospheric Chemistry and Physics Discussions, an online journal.

A team of scientists at Rutgers, The State University of New Jersey; the University of Colorado at Boulder (CU-Boulder); and UCLA conducted the rigorous scientific studies reported.

Against the backdrop of growing tensions in the Middle East and nuclear "saber rattling" elsewhere in Asia, the authors point out that even the smallest nuclear powers today and in the near future may have as many as 50 or more Hiroshima-size (15 kiloton) weapons in their arsenals; all told, about 40 countries possess enough plutonium and/or uranium to construct substantial nuclear arsenals.

Owen "Brian" Toon, chair of the department of atmospheric and oceanic sciences and a member of the Laboratory for Atmospheric and Space Physics at CU-Boulder, oversaw the analysis of potential fatalities based on an assessment of current nuclear weapons inventories and population densities in large urban complexes. His team focused on scenarios of smoke emissions that urban firestorms could produce.

"The results described in one of the new papers represent the first comprehensive quantitative study of the consequences of a nuclear conflict between smaller nuclear states," said Toon and his co-authors. "A small country is likely to direct its weapons against population centers to maximize damage and achieve the greatest advantage," Toon said. Fatality estimates for a plausible regional conflict ranged from 2.6 million to 16.7 million per country.

Alan Robock, a professor in the department of environmental sciences and associate director of the Center for Environmental Prediction at Rutgers' Cook College, guided the climate modeling effort using tools he previously employed in assessing volcano-induced climate change. Robock and his Rutgers co-workers, Professor Georgiy Stenchikov and Postdoctoral Associate Luke Oman (now at Johns Hopkins University) generated a series of computer simulations depicting potential climatic anomalies that a small-scale nuclear war could bring about, summarizing their conclusions in the second paper.

"Considering the relatively small number and size of the weapons, the effects are surprisingly large. The potential devastation would be catastrophic and long term," said Richard Turco, professor of atmospheric and oceanic sciences, and a member and founding director of UCLA's Institute of the Environment. Turco once headed a team including Toon and Carl Sagan that originally defined "nuclear winter."

While a regional nuclear confrontation among emerging third-world nuclear powers might be geographically constrained, Robock and his colleagues have concluded that the environmental impacts could be worldwide.

"We examined the climatic effects of the smoke produced in a regional conflict in the subtropics between two opposing nations, each using 50 Hiroshima-size nuclear weapons to attack the other's most populated urban areas," Robock said. The researchers carried out their simulations using a modern climate model coupled with estimates of smoke emissions provided by Toon and his colleagues, which amounted to as much as five million metric tons of "soot" particles.

"A cooling of several degrees would occur over large areas of North America and Eurasia, including most of the grain-growing regions," Robock said. "As in the case with earlier nuclear winter calculations, large climatic effects would occur in regions far removed from the target areas or the countries involved in the conflict."

When Robock and his team applied their climate model to calibrate the recorded response to the 1912 eruptions of Katmai volcano in Alaska, they found that observed temperature anomalies were accurately reproduced. On a grander scale, the 1815 eruption of Tambora in Indonesia -- the largest in the last 500 years -- was followed by killing frosts throughout New England in 1816, during what has become known as "the year without a summer." The weather in Europe was reported to be so cold and wet that the harvest failed and people starved. This historical event, according to Robock, perhaps foreshadows the kind of climate disruptions that would follow a regional nuclear conflict.

But the climatic disruption resulting from Tambora lasted for only about one year, the authors note. In their most recent computer simulation, in which carbon particles remain in the stratosphere for up to 10 years, the climatic effects are greater and last longer than those associated with the Tambora eruption.

"With the exchange of 100 15-kiloton weapons as posed in this scenario, the estimated quantities of smoke generated could lead to global climate anomalies exceeding any changes experienced in recorded history," Robock said. "And that's just 0.03 percent of the total explosive power of the current world nuclear arsenal."

So you mention and compare the great amount of the kilotons of the tests since end of WWII, and you put it into direct relation to the actual scenario, which is described in the article, bravo ... alone this shows the lack of understanding in this regard (when, which and how the tests were running, and in how far they could be compared to the investigated scenario). However, where is your proper source for the mere as claim expressed "Nuclear winter a myth?" (even if you seem to ask for the subject in matter, it sounds to me mainly like a claim). In conclusion, you need to come up with more than your guesses above, ie. a scientific counter-investigation.

Edit: It also should be moved to the Science section, fits not into History section, imo., so ie. somebody could search after the said simulation from 2006, and looking into it in detail.

Last edited by DaVinci; April 28, 2012 at 06:24 PM.

Die Welt wird nicht bedroht von den Menschen, die böse sind, sondern von denen, die das Böse zulassen.
Translation: The world is not threatened by the humans who are evil, but by the ones who let the evil happen.
Einstein

Re: Nuclear winter a myth?

Originally Posted by Rolling Thunder

Same here. We burned most of Germany and Japan to the ground in 1945 and it didn't seem to do much.

Yes, but try with almost every city in the world ( I have no idea what sort of places are targeted) all at once plus the mushroom cloud from the explosion itself, plus what conon said alot of fuel fires and forest fires going on afterwards, Its happened before with a massive meteor, it might happen again.

Australia: A land of bronzed bodies and wonderful football.

This signature is a solemn promise that no new Call of Duty game shall be purchased by me until a new engine is produced for the game.

Re: Nuclear winter a myth?

Nuclear weaponry is simply surrounded with hyperbole of this sort, not that it's necessarily a bad thing. A nuclear winter (as in "long term drop in temperatures that results in a possible extinction of humanity) is a myth, and studies saying it's possible usually assume that every single detonation would be a groundburst (soft targets like cities would be destroyed by airbursts), would produce a firestorm, and exaggarate the effects that those would have globally in the long term. Case in point: that study quoted above acknowledges that the Tambora eruption (equivalent to 800 megatons) did not produce a nuclear winter, but somehow 100 15kt bombs would produce soot that would stay in the athmosphere long enough to be worse.

Nuclear winter is a problematic concept. The TTAPS study that popularized it was based on the assumption that the Earth is a featureless ball of rock with no oceans. Subsequent studies usually assume that the soot thrown up by the detonations would linger in the athmosphere longer than soot from other sources, like volcanoes or more natural firestorms. And most crucially, they assume that every single detonation would result in a Dresden-like firestorm and that the firestorms would throw soot into the athmosphere forgetting that firestorms haven't been observed to do so in the manner their models predict. Simpy put, the effects their models assume nukes would have are far worse than there is reason to believe.

A nuclear war would without a doubt be extremely destructive, and would result in a temporary drop in temperatures but a long term nuclear winter is unlikely, and unsupported by evidence. But then, if the propagation of the myth makes it that much harder for nations to start nuclear wars, then it's kind of hard to argue against it.

Edit: The only nuclear detonation ever to produce a firestorm was the one over Hiroshima, and the soot sucked into the air rained down immediately afterwards. Yet for a nuclear winter to take place, every single detonation would have to produce a firestorm, and the dust and ash and other particles would have to stay in the athmosphere for years. If that doesn't happen then nuclear winter doesn't happen. The whole thing is based on a string of unfounded assumptions.

Re: Nuclear winter a myth?

Originally Posted by DukeofBrunswick

Yes, but try with almost every city in the world ( I have no idea what sort of places are targeted) all at once plus the mushroom cloud from the explosion itself, plus what conon said alot of fuel fires and forest fires going on afterwards, Its happened before with a massive meteor, it might happen again.

Why every city in the world? How on earth does that ing make sense?

You see, if I were, say, Russia, in a nuclear exchange with the USA, I wouldn't waste my nukes on Buenos Aires.

Re: Nuclear winter a myth?

Originally Posted by DukeofBrunswick

Yes, but try with almost every city in the world ( I have no idea what sort of places are targeted) all at once plus the mushroom cloud from the explosion itself, plus what conon said alot of fuel fires and forest fires going on afterwards, Its happened before with a massive meteor, it might happen again.

Yes, an asteroid impact might do the trick, and the K-T event asteroid impact produced what might be called equivalent to a nuclear winter. Trouble is, all the nuclear weapons combined at the height of the Cold War could not have produced even a fraction of the destructive power that the asteroid impact produced. The combined yield of the nuclear arsenals was at its height around 20,000 megatons, whereas the asteroid that made the Chicxulub crater had a force of 96 teratons! Humanity can not, and propably never can produce a destructive event that would result in a nuclear winter even if it tried to do just that.

Re: Nuclear winter a myth?

Originally Posted by irelandeb

No I want to debate whether they would have effects on the global climate.

A full scale nuclear war would absolutely have effects on the global climate. Soot thrown into the athmosphere would result in a drop of temperatures as less sunlight reaches the surface, but the dust particles would also absorb heat resulting in a warming effect. Ozone layer would experience a slight depletion, but the dust in the air would result in less ultraviolet light reaching the surface than before the war. A few months after the nukes have stopped flying (assuming the war escalated quickly to an all-out nuclear war) the temperatures would have reached their low, but the temperatures would only drop significantly in inland North-America and Eurasia; coastal areas would hardly be affected, and high in the athmosphere temperatures would be higher than normally. Due to less sunlight, growing season would shorten and famines all over the world would happen. In a few years, the athmosphere and temperatures would be back to normal, and at no point would the sun have been blotted out completely.

In short, the models predicting nuclear winter took the cooling effects a nuclear war would have and not only greatly exaggarated them, but also ignored all the factors that would off-set them. If the TTAPS model had factored in an ocean covering 2/3rds of their billiard-ball model of Earth, then they could not have predicted a nuclear winter. They assumed that every single detonation would result in a firestorm (which would not happen) and that every single firestorm would deposit soot into the upper athmosphere (which would not happen) and that the soot would stay there (which would not happen) resulting in the Earth being covered in a uniform 10-mile thick layer of soot that would stay there for years on end, with no winds or air currents factored in. It's fairly clear that they adjusted the model to get the effects they wanted, and did the same to later models to the extent they thought they could get away with.

Re: Nuclear winter a myth?

Here's an absolutely fantastic video that catalogs every nuclear detonation that has ever taken place since the Trinity Test in 1945. The only ones left out are the alleged N. Korean detonations in 2006 and 2009.

Colfax WA, neat I have a barn and 49 acres - I have 2 horses, 15 chickens - but no more pigs

Posts

10,968

Re: Nuclear winter a myth?

I demand to know why there were British nuclear tests on our soil. By God we don't need their filth here!

Oh come now my friend - filth is fine if they are willing to pay enough pounds sterling.

IN PATROCINIVM SVB Dromikaites

'One day when I fly with my hands - up down the sky, like a bird'

But if the cause be not good, the king himself hath a heavy reckoning to make, when all those legs and arms and heads, chopped off in battle, shall join together at the latter day and cry all 'We died at such a place; some swearing, some crying for surgeon, some upon their wives left poor behind them, some upon the debts they owe, some upon their children rawly left.

Hyperides of Athens: We know, replied he, that Antipater is good, but we (the Demos of Athens) have no need of a master at present, even a good one.